Field of the Invention
The present invention is directed to improvements to a tympanic lens for use in a light driven hearing aid system and, more particularly, to methods and apparatus which improve the frequency response of a tympanic lens for use in contact hearing aid systems.
Background
Contact hearing systems, such as those described herein, generally include a contact hearing device, an ear tip and an audio processor. Contact hearing systems may also include additional components, such as an external communication device. An example of such system is a light driven hearing-aid system that transmits audio signal by laser to a contact hearing device such as a tympanic membrane transducer (TMT) which is placed on an ear drum.
Contact hearing devices for use in contact hearing systems may comprise a tiny actuator connected to a customized ring-shaped support platform that floats on tissue in the ear canal on or around the eardrum, and resides in the ear much like a contact lens resides on the surface of the eye. In such contact hearing devices, the actuator directly vibrates the eardrum, causing energy to be transmitted through the middle and inner ears to stimulate the brain and produce the perception of sound. In some contact hearing systems, the contact hearing device may comprise a photodetector, a microactuator connected to the photodetector, and a support structure supporting the photodetector and microactuator.
Contact hearing systems may further include an Audio Processor (which may also be referred to as a BTE). The audio processor serves as a system for receiving and processing audio signals. Such audio processors may include one or more microphones adapted to receive sound which reaches the user's ear along with one or more components for processing the received sound and digital signal processing electronics and software which are adapted to process the received sound, including amplification of the received sound.
Contact hearing systems may also include ear tips which are adapted to fit into the ear of a user and transmit sound to the contact hearing device positioned at the distal end of the user's ear canal. Ear tips are designed to be placed into and reside in the ear canal of a user, where the structure is adapted to receive signals intended to be transmitted to the user's tympanic membrane or to a device positioned on or near the user's tympanic membrane (such as, for example, a contact hearing device). In light driven hearing aids, the signals may be transmitted by light using, for example, a laser positioned in the ear tip. In such light driven contact hearing systems, the ear tip may be referred to as a light tip.
In contact hearing devices, the movement of elements of the contact hearing device, including elements of a microactuator, may result in undesirable modes of vibration which cause resonant and/or anti-resonant modes of operation. When such resonant and/or anti-resonant modes of operation occur within frequency bands which are within the operating parameters of the contact hearing device (e.g., within the audio spectrum) it may negatively affect the operation of the contact hearing device. It would, therefore, be advantageous to design contact hearing devices to prevent resonant and/or anti-resonant modes of operation.